Re: Thoughts on whether the size change will be permanent?
 

I know our team would rather have the larger size, and we are running into a lot of space problems this year. I think the large size should be ok to use, but maybe suggest that new teams don't build big unless they can handle it. Whether constraint be time, money, resources, etc.

Re: Thoughts on whether the size change will be permanent?
 

A tangible benefit to the smaller robot sizes is not having to shove a bumper-mounted, bagged and tagged, 28"x38" robot through a standard door.

In the competition, this will cause much larger variety in design and strategy, something one could say was sorely needed after the last 3 or 4 years.

Re: Thoughts on whether the size change will be permanent?
 

Please note that bumpers are no longer required to be bagged. However, as pointed out above, 28" dimensions have ruled in the past to allow robots to move through standard 32" doors. If the GDC had wanted to make smaller robots, reducing the weight would have helped achieve that in many teams. Not thinking about the 28" max dimension but concentrating on the 112" perimeter might give you a hint.

Oh, while we are on the subject, please do not build to 28 x 28 and expect the frame perimeter to end up less than or equal to 112". Experienced teams will be building at least 1/4" less in every dimension to insure no problems during inspection.

Re: Thoughts on whether the size change will be permanent?
 

I think the size reduction this year has more to do with reducing the possibility of robots being able to legally impede the passage of the other alliance's robots as they seek to get past the pyramids. Couple the perimeter limit with the 54" cylinder to see why I think so. Also the creation of the update which shows the pyramids surrounded by a graphic boundary gives more support for my flow restriction theory.

Re: Thoughts on whether the size change will be permanent?
 

My impression was that the new perimeter rule was at least partially driven by a desire to eliminate the sizing box as a choke point in the inspection process. It will be interesting to see how it goes. The cynical part of me thinks the 'string around the 'bot' method has some room for error and ambiguity the sizing box did not. You're advice about designing well under the spec is hopefully heeded.

As long as we're sort of talking about it, am I the only one who would appreciate a weight reduction (of the robot)? 150lbs is quite a bit to expect teenagers to safely move around, frequently in a hurry. 100lbs would be a nice round number for the dry 'bot weight, which puts the wet weight at around 130lbs assuming the same battery and bumper rules. Sounds a bit more reasonable.

Re: Thoughts on whether the size change will be permanent?
 

Sounds good, until you are inspecting rookie robots Thursday morning that weigh 30 pounds too much, instead of just ten pounds too much :p

Re: Thoughts on whether the size change will be permanent?
 

I'm happy with the current weight restrictions,* and moving it hasn't been a problem for me/my team, provided we do it safely. If a team is conceerned about not being able to lift a 150 pound robot safely, then they should design their robot to be lighter. The end result of a self-imposed weight limit would be exactly the same as a FIRST-imposed weight ruling.

*Granted, I wouldn't mind a higher weight restriction, but I certainly don't have a problem with it being too high.

Re: Thoughts on whether the size change will be permanent?
 

I'm not sure I would like such a rule change.
Given that the field size is still the same, robot parts in general aren't going to be lighter, and the already smaller footprint.....its tough enough as it is trying to make weight.

Re: Thoughts on whether the size change will be permanent?
 

Smaller robots might mean more robots on the field at the same time. Something for the future?

Re: Thoughts on whether the size change will be permanent?
 

I think the smaller size is directly related to this year's challenge.

Think about it, if we had a 28" X 38" limit this year, 180 deg shooters would be easy to design and mount. Disk pickup and manipulation through the robot would not be nearly as challenging. Lifting systems would be just as much of a challenge, but still would have more room to work within.

The GDC did an amazing job with this year's challenge.
Honestly, I see no reason to keep a 112" perimeter limit in the future.... unless it makes the game a real challenge.

Re: Thoughts on whether the size change will be permanent?
 

Andy,
The sizing box was no more of a choke point than weighing. It also was a rather visual declaration to other teams that your robot made size. It either fits or it doesn't just like it is either 120 lbs or it is too heavy.

Cal,
While it may work for your team now, a smaller drive person may really struggle in the future. Realistically, we are asking students to lift 75 lbs. about 26 times minimum over a three day period. Pulled muscles and back pain is a real result. I have been concerned about the weight for a while and I only lift it a few times during build.

Re: Thoughts on whether the size change will be permanent?
 

Yes, but this year if you're 1/4" over you only need to take 1/4" off of a corner (actually only .707*1/4"), not an entire side of a robot. It's much easier to run up to the limit.

(As long as you can make the 1" bumper support at each end somehow - still haven't figured out how that works for sides that are <8", a chamfered corner, for example)

Re: Thoughts on whether the size change will be permanent?
 

I'm glad someone else noticed that :cool:

Re: Thoughts on whether the size change will be permanent?
 

As Al already pointed out the robot weight is nothing to sneeze at. A self imposed weight limit would simply put you at a disadvantage in the game, so it really isn't at all the same as a game rule.

I've worked in a warehouse setting and 80lbs was the most you were ever expected to lift on your own. That was, effectively, for grown men accustomed to lifting heavy loads. That's a pretty typical number from what I've seen, and workplace injuries from lifting heavy loads are still common (why OSHA hasn't set some regulations on this is beyond me).

150lbs has got to be the upper limit. Any higher and a robot simply can not be safely borne by two highschool students, and I suspect FIRST already recognizes this. A return to the ~130lb loaded weight would be a big step in the right direction. Since FIRST won't go back to no bumpers, and realistically the battery isn't going to change, that weight would have to come out of the robot. Oh well. Teams are always going to be busting the weight cap no matter where you set it, and will always complain that if only they had X more lbs to play with they could have done Y.

I'd just be happier if the dressed robot didn't weigh more then 90% of my teenage students, is all.

Re: Thoughts on whether the size change will be permanent?
 

Getting rid of the inspection box may well free up a bit of extra pit space in the more tightly-packed venues (the Waterloos of the world), and simplifies inspectors' logistics. But I suspect that the decision was also driven by the design of the boxes themselves.

The tolerancing on the sizing boxes was done incorrectly from the outset. They should have been designed and constructed with a geometric tolerance that inherently passes all legal robots, even given the degree of dimensional uncertainty in manufacturing the box.

Instead, the sizing boxes as delivered to events were occasionally undersized in places. Although FIRST's eventual change from the ratcheting strap on the shipping cart (which caused the front frame of the sizing box to bend like an hourglass), to a locking hard case saved them from wear and tear, in the first few years of those sizing boxes, on more than one occasion, the inspectors had to use brute force and/or fabricate gussets to expand the sizing box to an acceptable plus tolerance. (I believe the worst one I ever dealt with was about 0.15 in undersized in one corner, and 0.20 in undersized right down the middle.) All so that teams that built their robot with an ill-advisedly fine minus tolerance could (correctly) pass inspection with a minimum of delay.

All things being equal, it's better to risk passing a slightly oversized (illegal) robot than to risk failing a slightly undersized (legal) one. After all, the inspection apparatus are the embodiment of FIRST's rules; if the boxes are not designed to ensure that every legal robot will pass, teams will lose confidence in the apparently lackadaisical attention to specifications, and believe that the size restrictions are suggestions rather than hard limits. That makes the job harder for the inspectors, and in the long run, harder for FIRST as well. Next time they need a sizing box (or similar), they should consult with an engineer who works in gauge design for manufacturing.

The point of that anecdote is to illustrate why I suspect that FIRST decided that the sizing boxes were an unsustainable investment. They're probably worth well over $1 000 each, and you need one in good repair for every field set (of which there are probably 15 by now). Even if you realize that some of them are out of spec, it's hard to justify the cost of replacing them all. If you only fix the dimensions on the new ones, then some regionals get differently-enforced rules. This decision saves FIRST money in the long run, and saves them the headache of treating the sizing boxes like precision gauges.